Once you've announced your intent, can a committer then post a reply to this, officially proposing a vote for that person. This will kick-start the normal ASF processes which I'm sure we'd all want to follow anyway.
To make it clearer, I suggest that message titles are as follows:
Who wants to be a committer? <- this message
Re: Who wants to be a commiter? Alex Blewitt <- people who are interested in nominating themselves
[Vote] Re: Who wants to be a committer? Alex Blewitt <- a committer will have to officially launch the voting process off
Re: [Vote] Re: Who wants to be a committer? Alex Blewitt <- responses from other people (committers have the only binding votes, but support from the community is also a good indication)
Alex.
